Call recorder for telephone systems



Feb. 24, 1931. R. TILDEN ET AL CALL RECORDER FOR TELEPHONE SYSTEMSOriginal Filed June 17, 1925 FIG] 8 wR n & fi N l 2 53 m m a N: f mw 6 Vw 2 a 2 l V! F E A T TORNEV Patented Feb. 24, 1931 UNITED, STATES PATENTOFFICE ROBBINSTILDEN AND THOMA$ A. TILDEN, OF HIGH POINT, NORTH CAROLINACALL RECORDER FOR TELEPHONE SYSTEMS Application fi1ed J'une 1 7, 1926,Serial No. 116,590. Renewed NovemberS, 1928.

' This invention relates to electric signaling devices and has specialreference to a call recorder whereby one telephone station may call asecond station and record, at the 5 called station an indication, bydots, dashes,

perforations or otherwise the number or characteristic of the stationwhich has called.

In'other words, the invention embodies means for receiving and making apermanent record at a telephone station of the calls received from otherstations and also indicating onsuch permanent record the station fromwhich a call has been received, so that theuser of the telephonestation, in the event of his or her absence therefrom, may upon theirreturn, atonce perceive not only the number of calls that have come in,but also the telephone numbers of the stations from which said callshave been made and the order in which they have been made.

This device is preferable with automatic or machine switching equipment,that is, equipment that uses a calli'ng device or other forms of impulsetransmitters, senders or circuit breakers on telephone stations forsetting up and-operating apparatus in a proper manner for connecting onestation with any other station in the exchange or system, automatically,without the aid of human operators.

The purpose of the invention is to enable a telephone subscriber orstation to call any other telephone subscriber or station in thatparticular city or system and register at the 5 called station, by meansof dots, dashes or otherwise the number of the station calling. Thedevice is prferably connected in parallel j with the users telephone asan extension, and

using the same'line as that connected to the regular or main station.

The principle involved is to indicate on a suitable surface such as astrip of paper an "impression disclosing, upon the receipt of atelephone call, the number or other char- 4 acteristic of the callingstation. For instance, the telephone number of the calling station maybe automatically printed or written in the form of code-indications;these code indications may be in theform of dots or dashes. 4 Forinstance, the arrangement may be such that a telephone numbered 34:52calling a station equipped with the device described here in willregister on a strip or ribbon of paper, the proper number of marks andspaces, as hereafter explained in detail, which can bereadily'interpreted to read 3452.

Long distance operators in the central office, or any other particularoperator, employee or ioilicial of the telephone company could registertheir number by the machine as in the same case of any regular callingtelephone station. It could also be used in private systems, and couldbe used to replace complaint operators whose duties are to recordtelephones in trouble as subscribers re- 05 port the The inventionemploys peculiar circuit arrangements which involve slight changes inthe circuit of certain equipment (connectors) of the Strowger automaticequipment 7 and also of similar changes in other types of automatic ormachine switching equipment. However, the changes made do not impair inthe slightest degree the successful operation of such equipments nordoes it take away any of its particular features or improvements; nor dothese minor changes effect transmission over its circuit, or complicateit, to any noticeable extent. Such minor changes to be made by theoperating telephone company only in the group or groups having access tothe lines connecting with the'machine described herein.

It is noted that the use of this device is entirely under the control ofthe subscriber at able switch, connect the device for service when heleaves his office or house and during his presence at such oifice orhouse may disconnect the same. v

Business men in their offices, and any other class'of men and womenanywhere, may leave their oflices or other places equipped with thismachine described herein and all incoming calls will be registered andre-' corded in a permanent form in their proper order, automatically,during their absence,

thusdispensing with, in many cases a clerk left merely to answer andrecord telephone calls.

The principal and most important objects of the invention are to providean improved and novel construction of a device ofthis character torender the same, by improyed means, capable of recording in a permanentmanner code indications of the number of a-calling station; to improveand simplify. the wiring of such a device; to provide an improved meansin a device of this character for operating same bythe regular operatingexchange battery, thus eliminating any local battery at subscriberspremises; to provide means for indicating back to the calling subscriberthat he is connected with a station that has a device as described therein; and in general to provide a very simple, reliable and highlyefiicient device; indicating on-a permanent record the code numbers ofall subscribers stations calling his station. With the above and otherobjects in view as will be hereinafter apparent, the invention consistsin general of certain novel details of construction and combination ofparts hereinafter fully described, illustrated in the accompanyingdrawings and specifically claimedz Figure 1 is a diagrammatic view ofone form of the apparatus constructed in accordance with this invention.

Figure 2 shows a difi'erent arrangement accomplishing the same result;

Fig. 3 shows'a further modification applicable to the arrangements shownin Figs.

,, .In carrying out the objects of this invention, in Figure 1, there isprovidedan ordinary double pole switch or key 1 to which is connectedthe line'wires 2 and 3 leading to the particular subscribers station Thetelephone instruments themselves are not here shown as they do not enterdirectly into the invention, although certain parts ofsuch instrumentsdo co-operate with the invention, but as these parts are of wellknownforms it has not been deemed necessary to show drawing thereof, theshowing beingrestricted to a diagrammatic illustration. F romthis switch1 leads a wire 4 which is 'connected to oneterminal of the winding oftact spring 9 of relay coil 5.'- There is also provided another armature10 which is held normally against stop 11 by the tension of spring 12;there is a bushing 13 for holding down contact spring 9, so its contactswill remain in a make position as long as armature 10 is being energizedby coil 5. The make contact 14 is connected by a wire 15 to thecondenser 7,. This condenser 7 also has area another'wire 16 leading tocontact spring 17, i which when in normal position makes contact withswitch contact spring 18 and over Wire 19 to one terminal of the windingof coil 20, thence over wire 21 to contact spring 22, which, when in'itsmake position, establishes connection with contact spring 23, thenceover wire 24 to the other terminal of coil 20, over wire 25 back to thedouble pole switch 1. Armature 26 operated by magnet 5 is normally heldagainst adjustable stop 27 by tension of spring 28. At one end of thearmature 26 is a recording means 29 arranged to press against tape 30upon energi- -zation of magnet 5. The time wheel 31 meshes with wheels32, 33 and 34, and carries a cam 35 arranged to trip releasing arm ;36at each complete revolution. This releasing arm carries an insulatedbushing 37 at one end designed to break contact springs 17 and 18. Atthe otherv end of this releasing arm 36 is a dog 38, spring 39 holdingreleasing arm'36 normally against stop 40.

The operation of the apparatus as constructed in follows;

Switch or key 1 connects or disconnects the telephone number recordingapparatus from the subscribers line. switch is in the closed position(as is shown on drawing) ringing current from the central oflice orexchange intended to signal the called subscribers bells, will attractthe armature 9 of coil 5 over this circuit: Wire 2, switch 1, wire 25,coil 20, wire 19', contacts 18 and 17 in the normal or-closed position,wire 16, condenser 7 wire 6, coil 5, wire 4, switch 1, and wire 3.Armature 9 is under verylight spring tension, and will make with contact1 spring'll, during this ringing period. I This will short out thecondenser 7', over wire 8, contacts 9 and 14 and wire 15.

Shorting out this condenser will now cause the connector or similarequipment in centraloffice to cut off the alternating ringing currentand substitute direct current, or reguaccordance with Figure 1 is as l rexchange battery current. Coil 5' will now If the key or.

14. Armature 10 will catch in the d0g38 and I thus remains until dog 38is restored, regardless'of any changes in the subscribers line circuitor any variation or cessation in the current flowing through coil 5.Armature 10- releases wheel 32, which starts to rotate in the directionshown on drawing by arrow.

Wheels 32, 33, 34 and 31, together with paper plete revolution duringthe same period of time, so that always when wheel 31 is in the positionshown on drawing; wheel 32 shall also be in the position shown.

7 This will permit wheel 32 and paper thrust rollers 41 and 42 to rotatefor a short time after cam on wheel 31 has caused bushing 37 to opensprings 17 and 18 by means of the insulated bushing 37, thus causing anopen 1 space to appear on the paper tape 30 showing the division betweena complete operation of the device or the registration of a completecall number'and also more readily permits the user to tear off andobserve the code indications recorded" thereon by thrusting the paperand indications out.

The speed ofrotation of wheels 32, 33, 34 and 31, and the paper thrustrollers 41 and 42 is governed and is adjustable so that the proper timefor recording the number will elapse before the release of the machineas presently described, in.

order that the calling subscriber may have suificient time to dial hisown telephone number. varying from 2 to 10 digits according to the sizeof the exchange connected with. Cogs on wheel 34 will move spring 22rapidly to close and open with contact 23. This will alternately shortout coil 20, which will produce a distinctly audible and recognizabletone back to the calling subscriber, notifying him that the stationcalled has a machine of the character described herein and has connecteditself and is ready to receive his number. The calling subscriber,without restoring his receiver to the hook now proceeds to dial his ownnumber. The calling device, impulse sender or contact breaker, on histelephone rapidlyopens and closes the line circuit a number of timescorresponding to the number dialled. If the .dial is turned to 3, thecircuit is opened three times; if to 7 then it will be opened seven ticession. These impulses originating at the calling subscribers callingdevice, and com- 7 ing over the line to the called station will operatearmature 26 of coil 5, moving this armature backward and forward inaccordance with the number dialled. Armature 26 carries a recordingmeans 29 which will make a record of the number dialled on the strip ofmoving paper 30. This strip of paper 30 moves continuously and evenlyacross the re cording means 29, speed governed and powered by suitablegovernor and clockworlnand this continuous, even movement will cause allshort open spaces between the short dash marks or dots (these spacesrepresenting the digit dialled) to be similar and easily interpreted. Ashort dash or dot will appear sepmes in rapid suctelephone.

arating the open spaces that correspond to the digit recorded. Forexample: three short open spaces between long dashes represent thefigure three. A long dash (many times longer than the short dashreferred to above) will appear separating a digit of the complete callnumber. A long open space (many times longer than the short open spacerepresenting impulses forming the digit dialled) appearing on the paperdenotes the division between complete call numbers. These long dashesseparating digits of the call number and the long open spaces separatingthe complete call numbers are so much greater. in length that noconfusion could exist in distinguishing the code.

The next series of impulses coming over the line from the callingsubscribers dial, representing the second digit dialled, will berecorded on the moving paper tape 30 in like manner and so on until thecalling subscriber has dialled his complete number. To illustrate thisarrangement in a general way we will suppose Numbers 23l.and 425 desireto record their numbers with this device, the marks on the paper ribbonwill be as follows tinue to rotate until wheel 31 makes its completerevolution and cam 35 operates to restore dog 38 and opencontacts l7 and18. Armature 10, released by dog 38, restores to normal position,opening contacts 9 and 14, and in a short interval catches in stop camof wheel 32, preventing further rotation of wheel 32 and its associatedclockwork, wheels 33, 34, 31 and rollers 41 and 42. Wheel 31 is timed inits relation to wheel 32 so that the restoring cam 35 on wheel 31rotates far enough to permit dog 38 to rest against stop 40 or in theposition shown on drawing.

e recording'device is now fully released and in normal or idle position,ready for another call to come in and be recorded. It will be noted thatcondenser 7, while readily permitting the passage of alternating currentsuch as the ringing current intended to signal the called subscribersbells, it opens the circuit with reference to direct current, exchangebatter y ilor regular exchange operating current. ere is sufficientimpedance in coil 5 to not afi'ect transmission of conversation over thesubscribers telephone, if he should accidentally leave the switch 1 inthe closed position while he is present near the recording device, anddesire to answer the Of course during his absence from the telephone, aspreviously explained he will leave switch 1 in the closed position.

nected to one terminal of slow releasing re- This device maybe connectedto the line in such a manner that when the receiver hook is lifted touse the telephone, the recordingv device will be disconnected from theline.

If desired, wheel34 or.whee1 25, depending upon whether apparatussimilar to that shown inFigure 1 or in Figure 2 is employed, a couldhave a portion of its periphery beyond the point shown in contact withthe tone generating springs, smooth or free from teeth in order thata'few seconds could elapse before the tone was placed on the line backto the calling subscriber. This would permit the called subscriber toanswer the telephone after his bells had rung once, provided he 7happened to be present and desired to do so,

' itive of the subscribers loop. From switch or key 103 a wire 104 islead which is conlay coil 105. Another terminal of this co-il connectsover wire 106 with condenser 107 and with armature 108. From the otherterminal of condenser 107 leads a wire 109 connecting with one terminalof winding on inkwriter coil magnet 110; the other terminal of thisinkwriter magnet-is connected by wire'lll to switch103. Also connectingwith condenser 107 is a wire 112 which leads to contact 113; I Fromcontact 114 is a wire 115 leading to contact 116 of relay 105. Relay.coil "105 has a third' terminal connected to wire 117 and to (contact118. Contact 118 operates to make with contact 119 and is connected bywire 120 to wire 104. Coil 105 pperates dog 121 normally held againststop 122 by the tension of spring 123. Dog 121 is pivoted at 122a and isdesigned to catch instop pin 124a of wheel 124. Wheel 125 carries apinion 1-26 designed to mesh in the outer gear of wheeds 124 and 127.Wheel 127 has aflixed a cam or post 128 which operates ateachrevolutiommovable arm 129 be-- ing normally held against stop 130 bythe spring 131. This movable arm 129 carriesaj bushing 132 at one endfor breaking contacts 113 and 114. Upon energization of ink- 1 writercoil110 armature 133 is pulled away from adjustable stop 134 and againsttension of spring 135 causing recording means 136 to record on tape 137the electrical impulses received. Two rubber faced rollers 138 and frompaper roll 140, through recording Switch or key 103 is used to connector disconnect the recording device from subscribers line 101 and 102.With this switch in the closed or make position, ringing current fromthe central office intended to signal the bells of the called party,energizes coil 105 attracting armature 108 (which is a Verylight-armature under little tension) and moving'same to connect with itsmake contact 116. Tracing this circuit from switch 103: Wire 111,winding of coil 110, wire 109, condenser 107, wire 106, winding of coil105,

wire 104, to switch 103. A rmature 133 of coil 110 is under sufficienttehsion not to operate at this time with ringing current. When armature108 makes with contact116, a circuit is closed over wire 115, contact114,

and with movable arm 129 in normalposi tion, contact 113, wire 112 andto wire 109, cutting off central office ringing current andcausingconnector or other apparatus in cen-- tral oflice 'to furnishregular direct current in'kwriter magnetllO to energize their armatures.At this period dog 121 releases wheel 124, also setting. into motionwheels 125 and exchange battery causingrela'y coil 105 and 127 and paperextracting rollers 138 and 139,

which are operated by spring power or other suitable means. These wheelsand rollers are geared tb each other and are timedor speed regulated bygoverning means. Wheel 125 by teeth on its periphery causes impulsemaking spring 118.to make and brake contacts' 118 and 119, therebyshorting out part of coil winding 105, over wires 117 and 120 causing atone to be placed upon the line I which tone is heard by the callingsubscriber and thereby assuring him that the telephone station he hascalled has-a device of the characterdescribed herein, and notifying himthat such device is'inreadiness to receive and record his telephonenumber or'code designation. .Without hanging up, the calling party nowproceeds to dial his own telephone number These electrical impulses sentout from his impulse sender or calling device energizing anddeenergizing coil 110 in accordance with these impulses and therebycausing armature 133 with its recording finger 136 to'makesuitablelindications on tape 137.

These indications on tape 137 are in the form of marks and spaces, andwill always appear in a similar manner and are easily interpreted. Relycoil 105- being slow releasing does not respond to these impulses butwillhold its armature 108 and releasing dog 121 in the energizedposition, allowing wheels 124, 125 and 127 and rollers 138 and 139 tocontinue their rotation. These wheels and After the calling subscriberhas dialled his own number, he will restore his receiver to the hook,clearing his line. The recording device releases and clears out anyremaining apparatus participating .in the connection as follows:

When cam post 128 moves arm 129 the circuit is opened at contacts 113and 114, thereby deenergizing coil 105 and magnet 110 causing theirarmatures to restore to normal position and allowing releasing dog 121to catch in tooth of wheel 124 a short time later to allow rollers 138and 139 to rotate for an instant after recording finger 136 hasrestored; this causes an open space to appear on the tape separatingcomplete call numbers and also more readily permits the user to tear ofiand observethe code indications recorded thereon by thrusting the paperindications out. This stops the rotation of the timing wheels and therecording tape, which are geared together.

If desired to work this device on ground ringing duplex lines, wire 106from coil 105 would be connected to ground through a condenser.

Figure 3 shows how the recording finger may be attached to the armaturein such manner as to mark or print on the paper ribbon when in thereleased, inactive or normal position. This arrangement is applicabletothe apparatus as shown in Figure 1 or as shown in Figure 2. I

- In Figure 3, 201 is the magnet operating the recording means. 202 isan armature pivoted at 203 and normally held against adjdstable stop 204by the tension of spring 205. Attached to this armature 202 is arecording finger 206 which normally, or when magnet 201 is not excited,presses against paper ribbon 207. This paper ribbon is carried on a roll208 and guided past the adjustable table 209 by rollers 210. The rubberfaced rollers 211 and 212 rotate with the clockwork and pull the paperribbon 207 past recording finger 2 06 as well as guide and thrust, thefree end of paper out into clear view. 7

shown in Figure 3 will differ from that shown and explained underFigures 1 and 2 only in the printing or marking on the paper ribbon. Themarks and spaces appearing on the paper ribbon will be reversed inFigure 3. Marks will be substituted for spaces and spaces will besubstituted for marks. To use the same example as previously selected:Suppose that Numbers 231 and 425 desire to record their numbers withthis device the inarks onthe paper ribbon will be as folows:-

Since themind and eye are usually trained to observe marks rather thanthe lack of them or spaces, it may be preferable to use this arrangementover that shown in Figures 1 and 2, as it may be more readily understoodby the subscriber, though it will necessitate the obvious change in theordinary commercial form of inkwriter or similar machine. Such machinesare usually constructed to make an indication on the paper ribbon whenthe operating magnet is energized rather than deenergized as is the casewith apparatus shown constructed with the Figure 3 modification. Sincethe equipment shown in Figure 3 is exactly like that previouslyexplained in detail under explanations of Figures 1 and 2, it is notdeemed necessary to repeat the operation in detail. This change in theconstruction of the recording mechanism will cause the recorded numbersto appear according, to this method: The number of short dashesseparated by short spaces in a series, will indicate the digit; a longerdistinguishable open space will separate the digits in a call number,and-a longer distinguishable dash mark will separate complete callnumbers from each other. 7

A more elaborate arrangement combined with the special features shown inour application Serial Number 40,90O filed July 1, 1925, for LettersPatent in telephone call recorders, could be obtained by connecting alocal battery or an additional source of battery and repeating impulsesoriginating at the calling station, over a local circuit by anadditional impulse repeating relay. Since this arrangement would stillrecord the number of the calling station in the form of marks and openspaces instead of actual figures as shown in the application abovereferred to, it appears, on account of the greater simplicity and foreconomic reasons the device shown in Figures 1, 2 and- 3 of thisapplication is superior without additional battery, operating simply asan extension on the regular main telephone line.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the matep ,.rialspirit thereof. It is not therefore de- The operation of the recordlngdevice as sired to confine the invention to the exact form herein shownand described, but it is desired to include all such as properly comewithin the scope claimed. The expression number of the calling telephonestation, or similar expression, in the claims, is used as a briefexpression to indicate the individual designation of the callingtelephone station whatever that may be, whether numbers, words, lettersor a combination of any or all of these, or any other individualdesignation of a telephone that may be chosen.

What is claimed is: V

1. In a common battery electro-mechanical switching telephone systemhaving a regular exchange battery, means operated by the regular centraloflice exchange battery for indicating the number characteristic of thecalling telephone station at the called station,

such number characteristic being shown in a similar manner by marks andopen spaces on suitable material, and means for releasing the numberindicating apparatus. 7

2. Ina common battery electro-mechanical switching telephone systemhavin a regular exchange battery, means operated %y the regular centraloflice battery for recording by a suitably powered inkwriter, marks andopen spaces representing in a uniform code .the number characteristic ofthe calling telephone station, .at the called telephone station, andmeans for releasing the recording means.

- 3. In a common battery automatic electromechanical switching telephonesystem having a regular exchange battery and ringing current, meansoperated by the regular central oifice exchange ringing and batterycurrent for recording the number of the calling telephone station at thecalled telephone staing device and is in readiness toreceive and tion inthe-form of a uniform code of open spaces and marks on suitablematerial, and means for releasing the number recording means.

4. In a common battery electro-mechanical switching telephone systemhaving a regular exchange. battery and ringing-current, means operatedby the regular central oflice exchange ringing and battery currents forrecording the number of the calling telephone station at thecalledtelephone station, and means for informing the calling telephone stationthat the called-station is equipped with a record- 7 record the numberof the calling station.

5' In a common battery electro-mechanical switching telephone systemhaving a regular exchange battery current, means operated by the regularcentral office exchange common battery current for recording the numberof a calling telephone station at the called telephone station, andmeans operable after a suitable interval of time, for releasing saidnumber recording apparatus.

6. In a common battery electro-mechanical switching telephone systemhaving a regular exchange battery current, means operated by the regularcentral oflice exchange common battery currentfor recording the numberof the calling telephone station at the called telephone station, andmeans operable after a predetermined interval oftime for releasing saidnumber recording device.

7 In a common battery electro-mechanical switching telephone systemhaving a regular exchange battery current, means operated by weaves theregular central ofice exchange common battery current for recording thenumber of the calling telephone station at the called telephone station,means operable aftera suitable interval of time for releasing saidnumber recording apparatus, and means for automati- -cally placing theline in condition to receive number characteristic of a calling station,and

means for setting the recording device into operation by use of theregular exchange ringing current.

9. In a common battery .electro-mechanical switching telephone systemhaving a regular exchange battery current,'means operated by the regularcentral ofice exchange battery current for indicating the number tion atthe called telephone station, such number characteristics being. shownin a similar manner by marks and open spaces on a suitable material, andmeans for rendering the recorded number visible from-the exterior of therecording device.

10. In a common battery electro-mechanicharacteristic of the callingtelephone sta- 11. ha common battery electro-mechani-" cal switchingtelephone system having a regular exchange battery current, means oper-!ated by the regular central oflice exchange battery current forrecording marks and open spaces representin acteristic of the calhngtelephone station at the called tele hone station, and means for openingthe clrcuit to the regular operating exchange direct current, butproviding a path for alternating ringing current to set the recordingdevice into operation.

12. In a common battery electro-mechani cal switching telephone systemhaving a regular exchange battery current, means operated by the-regularexchange common battery current for indicating'the number characteristic of the calling telephone station at the called telephonestation, such number characteristic being shown at the called telethenumber char-v phone station by marks and open spaces impressed on asuitable surface, and meansfor providing distinguishable separationspaces between digits in a call number, and means for providing a moredistinguishable separation space between-complete call numbers. I

13. In a common battery electro-inechanical switching telephone systemhaving a regular exchange battery curre nt, means operated by theregular central oifice exchan e common battery current for indicating te number characteristic of a calling telephone station at a'calledtelephone station, such number characteristics being shown by marks andopen spaces impressed on a suitable surface, and means for feeding thesaid suitable surface through the recording device at a governed uniformspeed while the re: cording device is in operation to cause theindications thereon to constantly appear uniformly spaced with relationto each other.

14. In a common battery electro-mechanical switching telephone systemhaving a regular exchange battery current, means oper- 'tem.

ated by the regular central; ofiice exchange common battery current forrecording by means of a suitably powered inkwriter, marks and openspaces representing in a uniform code the number characteristic of acalling telephone station at the called telephone station, and means forconnecting and disconmeeting the recording device rom the sys- Intestimony that we claim the foregoing as our own we have signed ournames to this specification. y

' ROBBINS TILDEN.

THOMAS A. TILDEN'.

